Emulsions and microemulsions have been known as one of the dosage forms of agricultural chemicals, industrial preservatives, or the like. Emulsions (EW (emulsions, oil in water) or CE (concentrated emulsions)) are milky white formulations formed by emulsifying and dispersing an active ingredient insoluble in water as emulsion particles having an average particle size of about greater than 0.1 μm in water by an emulsifier. Microemulsions (ME) are transparent formulations formed by emulsifying and dispersing an active ingredient insoluble in water as fine emulsion particles having an average particle size of about 0.1 μm or less in water by an emulsifier. Emulsions or microemulsions can be obtained by diluting a composition containing an active ingredient insoluble in water, an emulsifier and other components with water, when used as agricultural chemicals or industrial preservatives.
A variety of compositions for obtaining an emulsion or microemulsion by dilution with water have been proposed.
For example, Patent Document 1 discloses a composition for wood preserving, termite repelling and antifungal agents that contains a polyoxyalkylene alkyl ether as an active ingredient.
Patent Document 2 discloses a composition containing an agrochemical active ingredient, a non-alcoholic organic solvent, an anionic surfactant and a nonionic surfactant (polyoxyalkylene alkyl ether or the like).
Patent Document 3 discloses a composition containing a cyclohexanedione-based herbicide, an aromatic hydrocarbon, a polyoxyethylene alkyl ether, and an alkylbenzenesulfonate amine salt.
Patent Document 4 discloses a composition containing an agrochemical active substance, an aromatic hydrocarbon, a polyoxyalkylene aryl phenyl ether, an alcohol such as decanol, and dialkylsulfosuccinate.
Patent Document 5 discloses a composition that contains an agrochemical active ingredient, an aromatic hydrocarbon, a polyoxyalkylene aryl phenyl ether and lauryl alcohol, but does not contain any of anionic surfactants and cationic surfactants.
Patent Document 6 discloses a composition containing a herbicidal active ingredient, a polyoxyethylene-polyoxypropylene block polymer as an emulsifier, a polyoxyethylene alkylamino ether and/or a higher alcohol as an emulsion stabilizer, an aromatic organic solvent and water.